The present invention relates to a method and an apparatus for presetting the three tools necessary for cutting and for the ejections of an automatic platen press for cutting cardboard box-blanks.
In the manufacture of box-blanks for cardboard packing cases it is known to employ automatic platen presses with three stations. In the first station there is mounted a cutting form made up of a rigid board, generally of wood, on one face of which cutting rules and creasing rules are fitted intended to respectively cut the cardboard box-blank according to the desired contour and to impress thereupon the different lines of creasing and of folding back. The box-blank, thus cut and scored, is seized by adequate gripping means along a border called a gripping engagement and entrained by transport means to the second station in which is mounted a board of first ejection having the same dimensions as the finished box-blank. The board of first ejection cooperates with a press cradle in order to strip the cutting wastes and eject them. The box-blank is finally conducted to the third station where there is disposed a board of second ejection which cooperates with a press cradle in order to sever the cut box-blank from the gripping engagement.
The known automatic platen presses of this type have the disadvantage of exhibiting, from one model to the other, dimensional differences, and, more particularly, differences in the margin left between the peripheral edge of the cutting form and the first cutting rule defining the edge of the box-blank. The result of this is that the tools of one press model cannot be utilized on another model.
Moreover, the registering of the tools relative to one another cannot be effected presently with sufficient precision, which entails an important loss of time in the setting of the tools as well as risks of imprecision shown by a poor cut of the box-blank or even a deterioration of the tools.